IBIC2023 - Classification: 04 Beam Loss Monitors and Machine Protection

Paper	Title	Page
TU3I01	Commissioning of the LCLS-II Machine Protection System for MHz CW Beams	154
	J.A. Mock, A.S. Fisher, R.T. Herbst, P. Krejcik, L. Sapozhnikov SLAC, Menlo Park, California, USA
	Beam power at the LCLS-II linac and FEL can be as high as several hundered kW with CW beam rates up to 1 MHz. The new MPS has a latency of less than 100 µs to prevent damage when a fault or beam loss is detected. The MPS architecture encompasses the multiple FEL beamlines served by the SC linac and can mitigate a fault in one beamline without impacting the beam rate in a neighboring beamline. The MPS receives inputs from various devices including loss monitors and charge monitors as well as magnet power supplies and BPMs to pre-emptively turn of the beam if a fault condition is detected. Link nodes distributed around the facility gather the input data and stream it back to a central processor that signals other link nodes connected to beam rate control devices. Commmissioning and experience with the new system will be described.
	Slides TU3I01 [4.239 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3I01
About •	Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 25 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU3C02	FPGA Architectures for Distributed ML Systems for Real-Time Beam Loss De-Blending	160
	M.A. Ibrahim, J.M.S. Arnold, M.R. Austin, J.R. Berlioz, P.M. Hanlet, K.J. Hazelwood, J. Mitrevski, V.P. Nagaslaev, A. Narayanan, D.J. Nicklaus, G. Pradhan, A.L. Saewert, B.A. Schupbach, K. Seiya, R.M. Thurman-Keup, N.V. Tran Fermilab, Batavia, Illinois, USA J.YC. Hu, J. Jiang, H. Liu, S. Memik, R. Shi, A.M. Shuping, M. Thieme, C. Xu Northwestern University, EVANSTON, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No.DE-AC02-07CH11359 with the United States Department of Energy. Additional funding provided by Grant Award No. LAB 20-2261 [1] The Real-time Edge AI for Distributed Systems (READS) project’s goal is to create a Machine Learning (ML) system for real-time beam loss de-blending within the accelerator enclosure, which houses two accelerators: the Main Injector (MI) and the Recycler (RR). In periods of joint operation, when both machines contain high intensity beam, radiative beam losses from MI and RR overlap on the enclosure¿s beam loss monitoring (BLM) system, making it difficult to attribute those losses to a single machine. Incorrect diagnoses result in unnecessary downtime that incurs both financial and experimental cost. The ML system will automatically disentangle each machine¿s contributions to those measured losses, while not disrupting the existing operations-critical functions of the BLM system. Within this paper, the ML models, used for learning both local and global machine signatures and producing high quality inferences based on raw BLM loss measurements, will only be discussed at a high-level. This paper will focus on the evolution of the architecture, which provided the high-frequency, low-latency collection of synchronized data streams to make real-time inferences. Performed at Northwestern with support from the Departments of Computer Science and Electrical and Computer Engineering
	Slides TU3C02 [17.830 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3C02
About •	Received ※ 07 September 2023 — Revised ※ 10 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 25 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU3C03	Collimator Scan Based Beam Halo Measurements in LHC and HL-LHC	164
	P.D. Hermes, M. Giovannozzi, C.E. Montanari, S. Morales Vigo, S. Redaelli, B. Salvachúa CERN, Meyrin, Switzerland M. Rakic EPFL, Lausanne, Switzerland
	Measurements in the CERN Large Hadron Collider (LHC) have indicated that the population of the transverse beam halo is greater than that of a Gaussian distribution. With the upcoming High Luminosity upgrade (HL-LHC), the stored beam energy in the beam halo could become large enough to threaten the integrity of the collimation system. Considerable efforts during the ongoing LHC Run 3 are dedicated to characterising the transverse beam halo, and its diffusion properties, after the LHC Injector Upgrade (LIU) in preparation for HL-LHC operation. Given the unprecedented stored beam energies of about 400MJ, presently achieved at the LHC, and about 700MJ planned at the HL-LHC, conventional measurements are difficult. Halo and diffusion measurements are currently based on collimator scans, where robust collimators are inserted in steps into the circulating beam halo. In this contribution, we present techniques for halo characterisation employed in LHC and compare results obtained from such measurements in LHC Run 2 and the ongoing LHC Run 3. We present plans for measurements in the remainder of LHC Run 3 and describe expected challenges for halo quantification in HL-LHC.
	Slides TU3C03 [5.876 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3C03
About •	Received ※ 05 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 11 September 2023 — Issue date ※ 12 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP002	Development of Bunch Position Monitors to Observe Sudden Beam Loss of SuperKEKB Rings	179
	M. Tobiyama, H. Ikeda, G. Mitsuka KEK, Ibaraki, Japan
	In the SuperKEKB rings, we have encountered extremely-fast beam losses occurring primarily within one to two turns in some parts of the bunch train. Such ¿sudden beam loss¿ induced severe failure in the vertical collimator heads, quenches on the superconducting final quadrupoles, and damage on the Belle II detector in some cases. Thus it is essential to investigate the cause and take countermeasures. This paper presents the phenomena clarified by the bunch current and position monitor of the bunch feedback system. The upgrade plan for the existing monitor, and recently developed simple monitors installed in the suspected area is also introduced.
	Poster TUP002 [0.727 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP002
About •	Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 27 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP004	Detector Response Studies of the ESS Ionization Chamber	183
	I. Dolenc Kittelmann, V. Grishin ESS, Lund, Sweden P. Boutachkov GSI, Darmstadt, Germany E. Effinger, A.T. Lernevall, W. Viganò, C. Zamantzas CERN, Meyrin, Switzerland
	The European Spallation Source (ESS), currently under construction in Lund, Sweden, will be a pulsed neutron source based on a proton linac. The ESS linac is designed to deliver a 2GeV beam with peak current of 62.5mA at 14 Hz to a rotating tungsten target for neutron production. One of the most critical elements for protection of an accelerator is a Beam Loss Monitoring (BLM) system. The system is designed to protect the accelerator from beam-induced damage and unnecessary activation of the components. The main ESS BLM system is based on ionization chamber (IC) detectors. The detector was originally designed for the LHC at CERN resulting in production of 4250 monitors in 2006-2008. In 2014-2017 a new production of 830 detectors with a modified design was carried out to replenish spares for LHC and make a new series for ESS and GSI. This contribution focuses on the results from a measurement campaigns performed at the HRM (High-Radiation to Materials) facility at CERN, where detector response of the ESS type IC has been studied. The results may be of interest for other facilities, that are using existing or plan to use new generation of LHC type IC monitors as BLM detectors.
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP004
About •	Received ※ 04 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 16 September 2023 — Issue date ※ 21 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP005	Commissioning the Beam-Loss Monitoring System of the LCLS Superconducting Linac	187
	A.S. Fisher, N. Balakrishnan, G.W. Brown, E.P. Chin, W.G. Cobau, J.E. Dusatko, B.T. Jacobson, S. Kwon, J.A. Mock, J. Park, J. Pigula, E. Rodriguez, J.I.D. Rudolph, D. Sanchez, L. Sapozhnikov, J.J. Welch SLAC, Menlo Park, California, USA
	A 4-GeV superconducting linac has been added to the LCLS x-ray FEL facility at SLAC. Its 120-kW, 1-MHz beam requires new beam-loss monitors (BLMs) for radiation protection, machine protection, and diagnostics. Long radiation-hard optical fibres span the full 4 km from the electron gun of the SC linac to the final beam dump. Diamond detectors at anticipated loss points provide local protection. Detector signals are continuously integrated with a 500-ms time constant and compared to a loss threshold. If crossed, the beam is halted within 0.1 ms. Commissioning began in March 2022 with the 100-MeV injector and with RF processing of the cryomodules. At IBIC 2022 last September, we presented commissioning results from the injector BLMs. In October, the beam passed through the full linac and the bypass transport line above the LCLS copper linac, stopping at an intermediate dump. In August it continued through the soft x-ray undulator and achieved first lasing. Here we present BLM commissioning at energies up to 4 GeV and rates up to 100 kHz. We discuss measurements and software using the fast diagnostic-waveform output to localize beam losses and to detect wire-scanner signals.
	Poster TUP005 [2.620 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP005
About •	Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 27 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP028	Collimator Irradiation Studies at the Advanced Photon Source	245
	J.C. Dooling, W. Berg, M. Borland, J.R. Calvey, L. Emery, A.M. Grannan, K.C. Harkay, Y. Lee, R.R. Lindberg, G. Navrotski, V. Sajaev, N. Sereno, J.B. Stevens, Y.P. Sun, K.P. Wootton ANL, Lemont, Illinois, USA N.M. Cook RadiaSoft LLC, Boulder, Colorado, USA D.W. Lee, S.M. Riedel UCSC, Santa Cruz, California, USA
	Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357. We present results from a recent collimator irradiation experiment conducted in the Advanced Photon Source (APS) storage ring. This experiment is the third in a series of studies to examine the effects of high-intensity electron beams on potential collimator material for the APS-Upgrade (APS-U). The intent here is to determine if a fan-out kicker can sufficiently reduce e-beam power density to protect horizontal collimators planned for the APS-U storage-ring. The fan-out kicker (FOK) spreads the bunched-beam vertically allowing it to grow in transverse dimensions prior to striking the collimator. In the present experiment, one of the two collimator test pieces is fabricated from oxygen-free copper; the other from 6061-T6 aluminum. As in past studies, diagnostics include turn-by-turn BPMs, a diagnostic image system, fast beam loss monitors, a pin-hole camera, and a current monitor. Post-irradiation analyses employ microscopy and metallurgy. To avoid confusion from multiple strikes, only three beam aborts are carried out on each of the collimator pieces; two with the FOK on and the other with it off. Observed hydrodynamic behavior will be compared with coupled codes.
	Poster TUP028 [3.733 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP028
About •	Received ※ 07 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 25 September 2023 — Issue date ※ 29 September 2023
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Commissioning of the LCLS-II Machine Protection System for MHz CW Beams

154

J.A. Mock, A.S. Fisher, R.T. Herbst, P. Krejcik, L. Sapozhnikov
SLAC, Menlo Park, California, USA

Beam power at the LCLS-II linac and FEL can be as high as several hundered kW with CW beam rates up to 1 MHz. The new MPS has a latency of less than 100 µs to prevent damage when a fault or beam loss is detected. The MPS architecture encompasses the multiple FEL beamlines served by the SC linac and can mitigate a fault in one beamline without impacting the beam rate in a neighboring beamline. The MPS receives inputs from various devices including loss monitors and charge monitors as well as magnet power supplies and BPMs to pre-emptively turn of the beam if a fault condition is detected. Link nodes distributed around the facility gather the input data and stream it back to a central processor that signals other link nodes connected to beam rate control devices. Commmissioning and experience with the new system will be described.

Slides TU3I01 [4.239 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3I01

About •

Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 25 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU3C02

FPGA Architectures for Distributed ML Systems for Real-Time Beam Loss De-Blending

160

M.A. Ibrahim, J.M.S. Arnold, M.R. Austin, J.R. Berlioz, P.M. Hanlet, K.J. Hazelwood, J. Mitrevski, V.P. Nagaslaev, A. Narayanan, D.J. Nicklaus, G. Pradhan, A.L. Saewert, B.A. Schupbach, K. Seiya, R.M. Thurman-Keup, N.V. Tran
Fermilab, Batavia, Illinois, USA
J.YC. Hu, J. Jiang, H. Liu, S. Memik, R. Shi, A.M. Shuping, M. Thieme, C. Xu
Northwestern University, EVANSTON, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No.DE-AC02-07CH11359 with the United States Department of Energy. Additional funding provided by Grant Award No. LAB 20-2261 [1]
The Real-time Edge AI for Distributed Systems (READS) project’s goal is to create a Machine Learning (ML) system for real-time beam loss de-blending within the accelerator enclosure, which houses two accelerators: the Main Injector (MI) and the Recycler (RR). In periods of joint operation, when both machines contain high intensity beam, radiative beam losses from MI and RR overlap on the enclosure¿s beam loss monitoring (BLM) system, making it difficult to attribute those losses to a single machine. Incorrect diagnoses result in unnecessary downtime that incurs both financial and experimental cost. The ML system will automatically disentangle each machine¿s contributions to those measured losses, while not disrupting the existing operations-critical functions of the BLM system. Within this paper, the ML models, used for learning both local and global machine signatures and producing high quality inferences based on raw BLM loss measurements, will only be discussed at a high-level. This paper will focus on the evolution of the architecture, which provided the high-frequency, low-latency collection of synchronized data streams to make real-time inferences.
Performed at Northwestern with support from the Departments of Computer Science and Electrical and Computer Engineering

Slides TU3C02 [17.830 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3C02

About •

Received ※ 07 September 2023 — Revised ※ 10 September 2023 — Accepted ※ 12 September 2023 — Issue date ※ 25 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU3C03

Collimator Scan Based Beam Halo Measurements in LHC and HL-LHC

164

P.D. Hermes, M. Giovannozzi, C.E. Montanari, S. Morales Vigo, S. Redaelli, B. Salvachúa
CERN, Meyrin, Switzerland
M. Rakic
EPFL, Lausanne, Switzerland

Measurements in the CERN Large Hadron Collider (LHC) have indicated that the population of the transverse beam halo is greater than that of a Gaussian distribution. With the upcoming High Luminosity upgrade (HL-LHC), the stored beam energy in the beam halo could become large enough to threaten the integrity of the collimation system. Considerable efforts during the ongoing LHC Run 3 are dedicated to characterising the transverse beam halo, and its diffusion properties, after the LHC Injector Upgrade (LIU) in preparation for HL-LHC operation. Given the unprecedented stored beam energies of about 400MJ, presently achieved at the LHC, and about 700MJ planned at the HL-LHC, conventional measurements are difficult. Halo and diffusion measurements are currently based on collimator scans, where robust collimators are inserted in steps into the circulating beam halo. In this contribution, we present techniques for halo characterisation employed in LHC and compare results obtained from such measurements in LHC Run 2 and the ongoing LHC Run 3. We present plans for measurements in the remainder of LHC Run 3 and describe expected challenges for halo quantification in HL-LHC.

Slides TU3C03 [5.876 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TU3C03

About •

Received ※ 05 September 2023 — Revised ※ 09 September 2023 — Accepted ※ 11 September 2023 — Issue date ※ 12 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP002

Development of Bunch Position Monitors to Observe Sudden Beam Loss of SuperKEKB Rings

179

M. Tobiyama, H. Ikeda, G. Mitsuka
KEK, Ibaraki, Japan

In the SuperKEKB rings, we have encountered extremely-fast beam losses occurring primarily within one to two turns in some parts of the bunch train. Such ¿sudden beam loss¿ induced severe failure in the vertical collimator heads, quenches on the superconducting final quadrupoles, and damage on the Belle II detector in some cases. Thus it is essential to investigate the cause and take countermeasures. This paper presents the phenomena clarified by the bunch current and position monitor of the bunch feedback system. The upgrade plan for the existing monitor, and recently developed simple monitors installed in the suspected area is also introduced.

Poster TUP002 [0.727 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP002

About •

Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 27 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP004

Detector Response Studies of the ESS Ionization Chamber

183

I. Dolenc Kittelmann, V. Grishin
ESS, Lund, Sweden
P. Boutachkov
GSI, Darmstadt, Germany
E. Effinger, A.T. Lernevall, W. Viganò, C. Zamantzas
CERN, Meyrin, Switzerland

The European Spallation Source (ESS), currently under construction in Lund, Sweden, will be a pulsed neutron source based on a proton linac. The ESS linac is designed to deliver a 2GeV beam with peak current of 62.5mA at 14 Hz to a rotating tungsten target for neutron production. One of the most critical elements for protection of an accelerator is a Beam Loss Monitoring (BLM) system. The system is designed to protect the accelerator from beam-induced damage and unnecessary activation of the components. The main ESS BLM system is based on ionization chamber (IC) detectors. The detector was originally designed for the LHC at CERN resulting in production of 4250 monitors in 2006-2008. In 2014-2017 a new production of 830 detectors with a modified design was carried out to replenish spares for LHC and make a new series for ESS and GSI. This contribution focuses on the results from a measurement campaigns performed at the HRM (High-Radiation to Materials) facility at CERN, where detector response of the ESS type IC has been studied. The results may be of interest for other facilities, that are using existing or plan to use new generation of LHC type IC monitors as BLM detectors.

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP004

About •

Received ※ 04 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 16 September 2023 — Issue date ※ 21 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP005

Commissioning the Beam-Loss Monitoring System of the LCLS Superconducting Linac

187

A.S. Fisher, N. Balakrishnan, G.W. Brown, E.P. Chin, W.G. Cobau, J.E. Dusatko, B.T. Jacobson, S. Kwon, J.A. Mock, J. Park, J. Pigula, E. Rodriguez, J.I.D. Rudolph, D. Sanchez, L. Sapozhnikov, J.J. Welch
SLAC, Menlo Park, California, USA

A 4-GeV superconducting linac has been added to the LCLS x-ray FEL facility at SLAC. Its 120-kW, 1-MHz beam requires new beam-loss monitors (BLMs) for radiation protection, machine protection, and diagnostics. Long radiation-hard optical fibres span the full 4 km from the electron gun of the SC linac to the final beam dump. Diamond detectors at anticipated loss points provide local protection. Detector signals are continuously integrated with a 500-ms time constant and compared to a loss threshold. If crossed, the beam is halted within 0.1 ms. Commissioning began in March 2022 with the 100-MeV injector and with RF processing of the cryomodules. At IBIC 2022 last September, we presented commissioning results from the injector BLMs. In October, the beam passed through the full linac and the bypass transport line above the LCLS copper linac, stopping at an intermediate dump. In August it continued through the soft x-ray undulator and achieved first lasing. Here we present BLM commissioning at energies up to 4 GeV and rates up to 100 kHz. We discuss measurements and software using the fast diagnostic-waveform output to localize beam losses and to detect wire-scanner signals.

Poster TUP005 [2.620 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP005

About •

Received ※ 06 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 13 September 2023 — Issue date ※ 27 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP028

Collimator Irradiation Studies at the Advanced Photon Source

245

J.C. Dooling, W. Berg, M. Borland, J.R. Calvey, L. Emery, A.M. Grannan, K.C. Harkay, Y. Lee, R.R. Lindberg, G. Navrotski, V. Sajaev, N. Sereno, J.B. Stevens, Y.P. Sun, K.P. Wootton
ANL, Lemont, Illinois, USA
N.M. Cook
RadiaSoft LLC, Boulder, Colorado, USA
D.W. Lee, S.M. Riedel
UCSC, Santa Cruz, California, USA

Funding: Work supported by the U.S. D.O.E.,Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02- 06CH11357.
We present results from a recent collimator irradiation experiment conducted in the Advanced Photon Source (APS) storage ring. This experiment is the third in a series of studies to examine the effects of high-intensity electron beams on potential collimator material for the APS-Upgrade (APS-U). The intent here is to determine if a fan-out kicker can sufficiently reduce e-beam power density to protect horizontal collimators planned for the APS-U storage-ring. The fan-out kicker (FOK) spreads the bunched-beam vertically allowing it to grow in transverse dimensions prior to striking the collimator. In the present experiment, one of the two collimator test pieces is fabricated from oxygen-free copper; the other from 6061-T6 aluminum. As in past studies, diagnostics include turn-by-turn BPMs, a diagnostic image system, fast beam loss monitors, a pin-hole camera, and a current monitor. Post-irradiation analyses employ microscopy and metallurgy. To avoid confusion from multiple strikes, only three beam aborts are carried out on each of the collimator pieces; two with the FOK on and the other with it off. Observed hydrodynamic behavior will be compared with coupled codes.

Poster TUP028 [3.733 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-IBIC2023-TUP028

About •

Received ※ 07 September 2023 — Revised ※ 08 September 2023 — Accepted ※ 25 September 2023 — Issue date ※ 29 September 2023

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)